CN-122010662-A - Method for preparing carbon dodecene by propylene tetramerization

Abstract

The invention belongs to the field of propylene oligomerization catalysis, and discloses a method for preparing carbon dodecene by propylene tetramerization, which comprises the steps of carrying out oligomerization reaction on propylene by using a solid acid-controlled supported sulfate catalyst, separating light components of carbon six and carbon nine olefins, and carrying out reflux and propylene co-oligomerization to generate the carbon dodecene, wherein the conversion rate of the propylene is 99.5%, and the total yield of the carbon dodecene is 75%. The invention converts low-value olefin into high-value carbon dodecene, greatly improves the economic value of the whole process, and in addition, the modification of the supported sulfate catalyst by the solid acid also effectively improves the conversion rate of propylene and the stability of the catalyst. The method has the advantages of environment-friendly reaction, mild conditions, high raw material utilization rate and good industrial application prospect.

Inventors

• LIANG CHANGHAI
• YANG JINYU
• CHEN XIAO

Assignees

• 大连理工大学

Dates

Publication Date

20260512

Application Date

20260204

Claims (5)

1. 1. A method for preparing carbon dodecene by propylene tetramerization, which is characterized by comprising the following steps: Step 1, dissolving aluminum oxide and sulfate in deionized water, uniformly stirring for 6-12h, removing free water through rotary evaporation to obtain a sulfate precursor loaded on the aluminum oxide, placing the sulfate precursor loaded on the aluminum oxide in a 100-120 o C oven for 6-12h, and then roasting in a tube furnace for 2-4h at 400-600 o C to obtain the sulfate loaded on the aluminum oxide; Step 2, mixing the sulfate loaded on the alumina obtained in the step 1 with solid acid in deionized water, uniformly stirring for 6-12 hours, removing free water through rotary evaporation to obtain a solid acid modified supported sulfate catalyst, placing the solid acid modified supported sulfate catalyst in a 100-120 o C oven for 6-12 hours, and then roasting in a tubular furnace for 2-4 hours at 400-600 o C to obtain the solid acid modified supported sulfate catalyst; And 3, carrying out propylene oligomerization reaction in a fixed bed reactor by taking propylene as a raw material and adopting a solid acid modified supported sulfate catalyst under the conditions of 30-180 o ℃ of temperature, 2-10MPa of pressure and 0.5-15h -1 of mass hourly space velocity, separating the product by a rectifying device, refluxing the product, carrying out co-oligomerization reaction with propylene, and separating the rest of olefin products with the purity of > C9 to obtain the carbon dodecene.
2. 2. The method for producing carbon dodecene by propylene tetramerization according to claim 1, wherein the sulfate is one of iron sulfate, cobalt sulfate and nickel sulfate, and a molar ratio of a metal element in the sulfate to an aluminum element is between 0.5 and 1.5.
3. 3. The method for producing carbon dodecene by propylene tetramerization according to claim 1, wherein the solid acid is one of chromic acid, tungstic acid, vanadic acid, molybdic acid, wherein the mass of the solid acid is 5% -15% of the total mass of the solid acid modified supported sulfate catalyst.
4. 4. The method for the tetramerization of propylene to carbon dodecene of claim 1, wherein the mass ratio of sulfate supported on alumina to solid acid is 95:5 to 85:15.
5. 5. The process for the tetramerization of propylene to carbon dodecene of claim 1, wherein the reflux ratio is 0.5 to 2.

Description

Method for preparing carbon dodecene by propylene tetramerization Technical Field The invention belongs to the field of propylene oligomerization catalysis, and relates to a method for preparing carbon dodecene by propylene tetramerization. Background The carbon dodecene is an organic chemical raw material with high reactivity, and has important application in a plurality of key industrial fields such as detergents, lubricating oil, polymers and the like due to the abundant chemical conversion potential. In the background of the continuous advancement of green chemical and biological manufacturing technologies, the use of carbon dodecenes is extending towards sustainable energy and materials, and future market demands are expected to steadily increase. In industrial applications, carbon dodecenes are key feedstocks for the production of Linear Alkylbenzenes (LABs). LAB is sulfonated to obtain linear sodium alkylbenzenesulfonate (LAS), which is a mainstream anionic surfactant and is widely used in daily chemical products such as laundry detergent, shampoo and the like, and occupies a main share of the global surfactant market. In addition, the poly alpha-olefin (PAO) lubricating oil synthesized by taking 1-dodecene as a raw material has excellent high-low temperature stability, oxidation resistance and thermal stability, is widely used for aeroengines, high-end automobile lubricating oil and industrial gear oil, and can effectively reduce equipment wear and prolong oil change period. The lubricating oil additive can also remarkably improve the viscosity index and the wear resistance of the oil product, and is suitable for the lubricating requirement under extreme working conditions. In the field of polymers, the carbon dodecene can be used as a comonomer for improving the performance of Polyethylene (PE) and polypropylene (PP), improving the flexibility, impact resistance and processing fluidity of materials, and is suitable for products such as food packaging films, medical instruments, automobile interiors and the like. Meanwhile, the carbon dodecenyl succinic anhydride (DOSA) can be derived from the carbon dodecenyl succinic anhydride, is used as an epoxy resin curing agent and a coating auxiliary agent, can enhance the adhesive force and chemical corrosion resistance of a coating, and is suitable for ship corrosion prevention, industrial coating and electronic packaging materials. In the field of energy, the high-purity carbon dodecene can be used as an aviation fuel additive, so that the combustion efficiency is improved, the carbon deposition generation is reduced, the emission of pollutants such as nitrogen oxides is reduced, and the energy conservation and carbon reduction aim of the aviation industry is realized. In addition, carbon dodecenes are also important raw materials for the synthesis of dodecyl mercaptan (used as a regulator of rubber polymerization) and dodecyl phenol (used as an antioxidant and as a surfactant intermediate). Therefore, development of a dodecene preparation method which is more focused on cost effectiveness and mass production has extremely important practical significance. Currently, with the widespread application of domestic propane dehydrogenation and coal-to-olefin technology, propylene productivity is significantly increased. How to convert propylene into high-value-added fine chemical products such as high-carbon olefin and the like has become a key for improving the industrial competitiveness. The development of propylene selective polymerization technology for preparing the carbon dodecene has extremely important significance for improving the added value of low-chain olefin, realizing the localization of the carbon dodecene and breaking through the technical problems in the fields of new materials and fine chemicals. At present, the propylene oligomerization technology widely adopted in industry has characteristics, but corresponding technical bottlenecks exist. The SPAC process uses phosphoric acid-diatomite as a catalyst, the process flow is simple, the raw material adaptability is good, the service life of the catalyst is short, and the injection water quantity must be accurately controlled in the reaction process. If the moisture is not properly controlled, the catalyst is liable to be agglomerated and deactivated, and may block pipelines and corrode equipment. The MOGD process adopts zeolite molecular sieve catalyst, so that the problem of water injection is avoided, but the catalyst is easy to deactivate due to carbon deposition in the reaction, and particularly, the process is obviously accelerated by impurities such as diolefins and the like in the raw materials. The Difasol process adopts a nickel complex catalyst system based on ionic liquid, the catalyst has good stability and is easy to separate, but the industrial application of the catalyst has the challenges that the reaction needs large-scale equipment, the post-treatment process of the product is